A heart valve prosthesis with a pair of pivotally mounted leaflets for replacing defective natural heart valves.
Heart valve replacements have been known to extend human life by providing improved blood circulation. Many different types of artificial heart valves have been made, for example a ball in a cage, the flat single disc, the conical disc, the flat bi-leaflet, the curved bi-leaflet, and the tissue valve.
In U.S. Pat. No. 4,178,639 to Bokros, diametrically opposite supports extend upwardly of an annular base and have spherically recessed portions for receiving the leaflet pivot ears. The surfaces for stopping the leaflets in the open position are located above the base, as are the leaflet pivot ears. The base has a circular edge for acting as a stop when the leaflets move toward their valve closed position.
U.S. Pat. No. 5,061,278 to Bicer discloses an annular base having axially intermediate bores extending radially therethrough for mounting bearing inserts. Each valve member has opposite axle members pivotally extending into opposite bearing inserts, the valve members in their closed position being curved in the direction of extension of one valve member from the other. This can result in eddies and turbulence in blood flow. Further, the structure for pivotally mounting the leaflets provides grooves around the pivot where thrombic tissue can form.
U.S. Pat. No. 4,451,937 to Klawitter discloses an annular base having diametrically opposite chordal segments that appear to have parallel flat surfaces with arcuate depressions formed therein to have generally rectangular ears of the flat leaflets extended thereinto. Peg-like protrusions that extend into the blood passage arcuately intermediate the chordal segments to limit movement of the leaflets to their closed position would act to obstruct blood flow.
Each of the known prior art artificial heart valves displays certain deficiencies that are peculiar to their own design. In order to minimize or overcome various deficiencies of prior art heart valves, this invention has been made.